The present invention relates to a safety device for preventing roofers or other workers from falling off of a roof.
In the past, different techniques of preventing injury to a roofer in the event of a fall have been developed. These techniques have varied from a net or a cushioned pad on which the roofer would land to various tether devices adapted to catch the worker.
Cushioned pads have the disadvantage that they do not help prevent the fall, rather, they simply reduce the likelihood of an inury. Injuries are still possible, however, if the roofer is in an awkward position with he hits the pad. Also, an effective pad system would require pads to be placed at every location that a roofer could possibly fall, thus requiring a large number of pads and a rather lengthy process of putting the pads in place. Transportation of the pads would be difficult due to their necessary bulk. Also, a pad system would do nothing to prevent sudden uncontrolled movements by an off-balance worker that could also lead to an injury. Net systems would basically have the same inherent difficulties.
A safety device for use by workmen on steel structures is disclosed in U.S. Pat. No. 3,217,833. This device essentially consists of a pair of adjustable jaw members which are designed to slidably grip the flange of a steel I-beam. An elongated bar is attached at one end to the jaw members and, at the other end, is connectable to a safety belt worn by the workman. This structure only allows movement by the worker along the particular beam to which the jaw members are attached, and would not be adaptable for use on a roof.
U.S. Pat. No. 3,237,717 discloses an apparatus that is mounted on a roof to provide anchoring points for a roofer. A plurality of brackets are provided on the roof and are inter-connected by rigid connecting rods. A flexible strap element is connected to the rigid rods in order to anchor a worker. The major shortcoming with this system is that it requires substantial rigging which would not be easily installed. Additionally, the extensive network of brackets and connecting rods obstruct the worker's movements and access to certain portions of the roof.
A simple tether device which is adapted to be fastened to a peaked roof is disclosed in U.S. Pat. No. 4,249,713. A strip of metal is bent to provide a connector having a central portion and two extending leg portions. The extending leg portions are provided with openings through which a nail can be driven to attach the connector to the peak of the roof. A safety line is clipped to an aperture in the central portion of the connector. In order to allow the worker sufficient mobility on the roof, the safety line must be relatively lengthy, thereby increasing the distance a roofer would fall before he is caught, particularly when he is working near the connector. Also, since the safety line is at the roof level, it provides somewhat of a hazard in that a worker could easily trip over it. Further, it is an added obstruction to movement and subject to entanglement with roofing materials or tools on the roof surface.
Another tether device is disclosed in U.S. Pat. No. 4,171,032. A bent pole is rotatably supported by a vertical sleeve secured to a side of a structure on which a man is working. A safety line is suspended from the upper end of the pole. Though the rotatable pole allows an increase in the mobility of the worker, the safety line still must be sufficiently long to permit the worker to work near the sleeve. This lengthy safety line has the same disadvantage discussed above. Several difficulties arise in attempting to use this device on a sloped roof. If the roof an overhang, there would be no way to attach the vertical sleeve to the side of the structure in a position that would receive the pole. Also, the fixed angle of the bent pole would lead to problems due to the slope of the roof.
While to social and human advantages of an adequate safety system for roofers are apparent, financial considerations also indicate a long felt need for an arrangement which does not slow or impede a worker in carrying out his normal work when in use, but also provide financial reward for using such a safety arrangement. In particular, one of the significant costs of installing or replacing roofs is insurance of workers. The cost per worker is on the order of $50-$20 per day. Accordingly, a suitable safety device that roof workers will actually use is of great economic and social importance to the workers, employers and building owners.